1. Field of the Invention
The present disclosure relates to refrigeration systems, and more particularly to refrigeration systems having a subcooling unit.
2. Description of Related Art
Refrigerated air conditioning systems utilize a thermal transfer cycle commonly referred to as the vapor-compression refrigeration cycle. Such systems typically include a compressor, a condenser, an expansion or throttling device and an evaporator connected in serial fluid communication with one another forming an air conditioning or refrigeration circuit. The system is charged with a condensable refrigerant (e.g., R-22 or R-410A), which circulates through each of the components in a closed loop. More particularly, the refrigerant of the system circulates through each of the components to remove heat from the evaporator and transfer heat to the condenser. The compressor compresses the refrigerant from a low-pressure superheated vapor state to a high pressure superheated vapor thereby increasing the temperature, enthalpy and pressure of the refrigerant. The refrigerant leaves the compressor and enters the condenser as a vapor at some elevated pressure where it is condensed as a result of heat transfer to cooling water and/or ambient air. The refrigerant then flows through the condenser condensing the refrigerant at a substantially constant pressure to a saturated-liquid state. The refrigerant then leaves the condenser as a high pressure liquid. The pressure of the liquid is decreased as it flows through the expansion or throttling valve causing the refrigerant to change to a mixed liquid-vapor state. The remaining liquid, now at low pressure, is vaporized in the evaporator as a result of heat transfer from the refrigerated space. This low-pressure superheated vapor refrigerant then enters the compressor to complete the cycle.
Typical refrigerated air conditioning systems are split into a “hot” side and a “cold” side. The hot side includes the condenser and the compressor with a fan near the condenser to disperse the heat generated by the system. The cold side includes the evaporator, the expansion valve and a second fan near the evaporator to route the cooled air towards the intended space.
Generally, performance of conventional systems decreases quickly with hot ambient conditions. Currently several technologies exist to improve system performance in hot ambient conditions such as subcoolers, economizers, work recovery devices and tube/suction line heat exchangers (SLHX). These typically require modification to existing systems.
Such conventional methods and systems have generally been considered satisfactory for their intended purpose. However, there is still a need in the art for improved cooling systems. The present disclosure provides a solution for this need.